U.S. Pat. No. 4,408,908 to Applegate et al discloses a ribbon feed in which the ribbon is held between closed surfaces until the ribbon feed reaches a certain tension. The ribbon pulls on an arm which is rotated at the increased tension, to then physically contact and rotate a second member to open the closed surfaces and free the ribbon. This keeps sufficient tension on the ribbon to hold it on its feed path. The closed surfaces constitute a lock or brake which holds the ribbon from any feed from the ribbon supply until a desired, predetermined tension is reached. This avoids the feeding variations and inaccuracies which tend to occur when the ribbon tension is variable and uncertain.
IBM Technical Disclosure Bulletin article entitled "Molded Ribbon Cartridge With Brake" by J. A. Craft, Vol. 25, No. 12, May 1983, at pp. 6676-6677 shows a mechanism molded as part of a cartridge having a resilient brake arm closing on the ribbon and a separate, tension-spring arm. As the ribbon tension increases, the tension-spring arm is moved to a position at which it physically contacts the brake arm to open the closed surfaces and free the ribbon.
U.S. Pat. No. 4,468,139 to Hattori shows closed surfaces to apply ribbon tension during feeding. U.S. Pat. No. 4,402,621 to Abell, Jr. et al shows a spring around which the ribbon passes applying continuous tension to the ribbon, with no positive brake. Both of those mechanisms are incorporated in the ribbon cartridge. Applying some tension between a supply roll and a feed roll is common, as is incorporating some of those mechanisms in a ribbon cartridge. Accordingly, these patents are considered only representative of a variety of similar teachings.